If you don't tell us where you're trying to go, any road will get you there...

I assume you want to simplify the expression -- but your notation is a bit strange. Is "ab" a single symbol or does it signify multiplication? I assume the period means multiplication. I'll assume the overbars denote negation, so look up De Morgan's Laws for some help to get started.

sorry about that, yes i need to simplify it so that the final expression is a Sum of Product expression with no bar appearing in the expression. I'll keep looking into it, the textbook been used brushes over the topic with only 1 example which seems to be much easier. sooo frustrating